A residential area near the Hampton Country Club in north-central Iowa has for years exceeded its ammonia and bacteria limits for wastewater that is discharged into a creek, according to the Iowa Department of Natural Resources.
The area north of Hampton uses a lagoon to store wastewater from about 63 dwellings. The lagoon relies on microbes to cleanse the water, which is then periodically released into Otter Creek, a tributary of the West Fork Cedar River.
The treatment system is operated by the Terrace Hill Sanitary Sewer District, which was instructed by the DNR to update the system before new contaminant limits became effective in 2021. Terrace Hill had about five years to complete the work but failed to, a DNR order said.
The system has since violated the new requirements 23 times. It discharged ammonia nitrogen in concentrations up to about seven times its limit and bacteria that exceeded 400 times the limit, according to DNR data.
Terrace Hill had contemplated a connection to Hampton’s wastewater treatment facility, but it was deemed too expensive by members of the homeowners association, said Sheila Bly, a senior environmental specialist for the DNR. The estimated cost was about $2 million.
Instead, Terrace Hill might expand its lagoon system, Bly said. The department recently ordered the sewer district to submit a plan by September and complete the upgrades by May 2028.
The DNR also fined Terrace Hill $2,500.